On 05/17/2013 11:19 AM, Sergey Naumov wrote:
But I've read in some sources (for example
http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc)
that seed list MUST include at least one seed from each DC and seed
lists should be the same for each node.
Or it is fine if nodes from new DC have all seeds specified and nodes
from old DCs have all seeds specified except seeds from new DC? In
such interpretation rules have to be a bit modified:
I never have problems with adding new nodes and new DC having single
seed per cluster in one old DC.
1. Nodes from the same DC should have identical seeds lists.
2. At least at one DC nodes MUST have in its seed lists seeds from all
other DCs.
2013/5/17 Igor <i...@4friends.od.ua <mailto:i...@4friends.od.ua>>
I see no reason to restart all nodes. You can continue to use seed
from first DC - seed used for loading ring
configuration(locations, token ranges, etc), not data.
On 05/17/2013 10:34 AM, Sergey Naumov wrote:
If I understand you correctly, GossipingPropertyFileSnitch is
useful for manipulations with nodes within a single DC, but to
add a new DC without having to restart every node in all DCs
(because seeds are specified in cassandra.yaml and I need to
restart a node after addition of a new seed from newly created
DC), I anyway have to use cassandra-topology.properties and edit
it on every node of a cluster.
By the way, it it necessary to specify seeds if I use
PropertyFileSnitch and there is info in
cassandra-topology.properties about all nodes of a cluster?
Yes, it is. Cassandra need seed(s), because topology properties
have no info about token ranges.
2013/5/17 aaron morton <aa...@thelastpickle.com
<mailto:aa...@thelastpickle.com>>
You should configure the seeds as recommended regardless of
the snitch used.
You need to update the yaml file to start using the
GossipingPropertyFileSnitch but after that it reads the
cassandra-rackdc.properties file to get information about the
node. It reads uses the information in gossip to get
information about the other nodes in the cluster.
If there is no info in gossip about a remote node, because
say it has not been upgraded, it will fall back to using
cassandra-topology.properties.
Hope that helps.
-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 15/05/2013, at 8:10 PM, Sergey Naumov <sknau...@gmail.com
<mailto:sknau...@gmail.com>> wrote:
> As far as I understand, GossipingPropertyFileSnitch
supposed to provide more flexibility in nodes
addition/removal. But what about addition of a DC? In
datastax documentation
(http://www.datastax.com/docs/1.2/operations/add_replace_nodes#add-dc)
it is said that cassandra-topology.properties could be
updated without restart for PropertyFileSnitch. But here
(http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc)
it it said, that "you MUST include at least one node from
EACH data center. It is a best practice to have at more than
one seed node per data center and the seed list should be the
same for each node". At the first glance it seems that
PropertyFileSnitch will get necessary info from
cassandra-topology.properties, but for
GossipingPropertyFileSnitch modification of cassandra.yaml
and restart of all nodes in all DCs will be required. Could
somebody clarify this topic?
>
> Thanks in advance,
> Sergey Naumov.
